The objective is identify various fluorescent biochemical and morphological components in bladder tissues using fluorescence microscopy. Frozen sections of bladder tissue were imaged with a fluorescent microscope. Serial sections were stained and reviewed by a pathologist. At 370 nm and 400 nm excitation, invasive cancer had little fluorescence other than what appeared to be scattered tiny collagen fragments and occasional inflammatory cells. For the other tissue diagnoses, epithelium had either no or undetectable fluorescence. Collagen strands in the submucosa, appearing as blue strings, were the primary fluorophore, although occasional yellowish-green spots that seem to be inflammatory cells also appeared. The lack of fluorescence of the invasive cancer explains the much weakened fluorescence spectra observed. The absence of epithelial fluorescence was not expected based on the observation earlier of dysplastic crypt cell fluorescence in the colon. In images ta ken of CIS, the submucosa exhibited fewer fluorescencing collagen strands, but in view of recent cystectomy results, the corresponding stained slides need to be closely checked for edema or hemorrhage which might play a role in this change in the submucosa. Analysis and interpretation of these microscope images is still ongoing.